Multiple disk friction clutches for automotive and other purposes generally comprise an internally toothed or splined outer member and an externally toothed or splined inner member, the two members being relatively rotatable but frictionally interconnectable by a disk pack or stack disposed between the members.
The outer member can have disks which are externally toothed for rotatable entrainment by the outer member, the splines or teeth of the latter enabling axial displacement of these disks. Similarly, the disks of the inner member can be internally toothed for rotatable engagement with the inner member and axial displacement relative thereto. The disks of the inner member are interleaved with the disks of the outer member.
One of the problems with multiple disk clutches of this type is the tendency of the disks to wobble, this movement being termed "disk flutter" and resulting in localized wear, overheating, increased drag or friction and disk distortion when the clutch is disengaged.
There have been various proposals to eliminate or reduce disk flutter. For example, in German patent document No. 17 50 748, it is proposed to subject the disks during operation to the influence of a rotating imbalance produced by centrifugal force, thereby tending to maintain the disks in positions in which they are perpendicular to the axis of rotation.
This arrangement, however, increases the frictional engagement between the disks and the rotating member which increases the force necessary to shift the clutch into its engaged state, i.e. the force required for axial displacement of the disks.
In another system described in German patent document No. 27 42 710, the disks are partly cut away. This, however, has not been found to be fully effective for the purpose.